/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @author Alexander Y. Kleymenov
 */

package org.apache.harmony.security.x509;

import org.apache.harmony.security.asn1.ASN1BitString;
import org.apache.harmony.security.asn1.ASN1Sequence;
import org.apache.harmony.security.asn1.ASN1Type;
import org.apache.harmony.security.asn1.BerInputStream;
import org.apache.harmony.security.asn1.BitString;
import org.apache.harmony.security.utils.Array;

/**
 * The class encapsulates the ASN.1 DER encoding/decoding work with the X.509
 * CRL. Its ASN notation is as follows (as specified in RFC 3280 - Internet
 * X.509 Public Key Infrastructure. Certificate and Certificate Revocation List
 * (CRL) Profile. http://www.ietf.org/rfc/rfc3280.txt):
 * 
 * <pre>
 *  CertificateList  ::=  SEQUENCE  {
 *       tbsCertList          TBSCertList,
 *       signatureAlgorithm   AlgorithmIdentifier,
 *       signatureValue       BIT STRING  
 *  }
 * </pre>
 */
public class CertificateList {

	// the value of tbsCertList field of the structure
	private final TBSCertList tbsCertList;
	// the value of signatureAlgorithm field of the structure
	private final AlgorithmIdentifier signatureAlgorithm;
	// the value of signatureValue field of the structure
	private final byte[] signatureValue;
	// the ASN.1 encoded form of CertList
	private byte[] encoding;

	/**
	 * X.509 CertList encoder/decoder.
	 */
	public static final ASN1Sequence ASN1 = new ASN1Sequence(new ASN1Type[] {
			TBSCertList.ASN1, AlgorithmIdentifier.ASN1,
			ASN1BitString.getInstance() }) {

		@Override
		protected Object getDecodedObject(BerInputStream in) {
			final Object[] values = (Object[]) in.content;
			return new CertificateList((TBSCertList) values[0],
					(AlgorithmIdentifier) values[1],
					((BitString) values[2]).bytes, // FIXME keep as BitString
													// object
					in.getEncoded());
		}

		@Override
		protected void getValues(Object object, Object[] values) {

			final CertificateList certlist = (CertificateList) object;

			values[0] = certlist.tbsCertList;
			values[1] = certlist.signatureAlgorithm;
			values[2] = new BitString(certlist.signatureValue, 0);
		}
	};

	/**
	 * TODO
	 * 
	 * @param tbsCertList
	 *            : TBSCertList
	 * @param signatureAlgorithm
	 *            : AlgorithmIdentifier
	 * @param signatureValue
	 *            : byte[]
	 */
	public CertificateList(TBSCertList tbsCertList,
			AlgorithmIdentifier signatureAlgorithm, byte[] signatureValue) {
		this.tbsCertList = tbsCertList;
		this.signatureAlgorithm = signatureAlgorithm;
		this.signatureValue = new byte[signatureValue.length];
		System.arraycopy(signatureValue, 0, this.signatureValue, 0,
				signatureValue.length);
	}

	//
	// TODO
	// @param tbsCertList: TBSCertList
	// @param signatureAlgorithm: AlgorithmIdentifier
	// @param signatureValue: byte[]
	// @param encoding: byte[]
	//
	private CertificateList(TBSCertList tbsCertList,
			AlgorithmIdentifier signatureAlgorithm, byte[] signatureValue,
			byte[] encoding) {
		this(tbsCertList, signatureAlgorithm, signatureValue);
		this.encoding = encoding;
	}

	/**
	 * Returns ASN.1 encoded form of this X.509 TBSCertList value.
	 * 
	 * @return a byte array containing ASN.1 encode form.
	 */
	public byte[] getEncoded() {
		if (encoding == null) {
			encoding = CertificateList.ASN1.encode(this);
		}
		return encoding;
	}

	/**
	 * Returns the value of signatureAlgorithm field of the structure.
	 * 
	 * @return signatureAlgorithm
	 */
	public AlgorithmIdentifier getSignatureAlgorithm() {
		return signatureAlgorithm;
	}

	/**
	 * Returns the value of signatureValue field of the structure.
	 * 
	 * @return signatureValue
	 */
	public byte[] getSignatureValue() {
		final byte[] result = new byte[signatureValue.length];
		System.arraycopy(signatureValue, 0, result, 0, signatureValue.length);
		return result;
	}

	/**
	 * Returns the value of tbsCertList field of the structure.
	 * 
	 * @return tbsCertList
	 */
	public TBSCertList getTbsCertList() {
		return tbsCertList;
	}

	@Override
	public String toString() {
		final StringBuffer res = new StringBuffer();
		tbsCertList.dumpValue(res);
		res.append("\nSignature Value:\n"); //$NON-NLS-1$
		res.append(Array.toString(signatureValue, "")); //$NON-NLS-1$
		return res.toString();
	}
}
